There’s nothing quite so interesting as the social interactions in the wolf pack. Wolves live in packs of about 6 to 10 members. Pack formation is possible because wolves are highly social creatures that develop strong bonds with one another. One of the ways in which wolves interact is through howling. A wolf’s howl is a vocalization, which means that it’s a sound produced in order to communicate. But what are they communicating, and with whom? Wolves howl to communicate their location to other pack members and to ward off rivaling packs from their territory. It’s also been found that wolves will howl to their own pack members out of affection, as opposed to anxiety.

Wolf packs tend to claim large territories for themselves, especially if prey is scarce. These territories can be as large as 3,000 square km (1,200 square miles). Wolves may separate from their packs when hunting, so howling becomes an effective way to communicate about location. A wolf’s howl can carry up to 16 km (10 miles) in the open tundra and a bit less in wooded areas.

Another sort of howl is an aggressive howl to other packs. It warns other packs or individual wolves in the area to stay away from the territory. A pack will also mark territory by using urine and feces.

A 2013 study added an additional reason behind wolves’ howls: affection. The study found that wolves tend to howl more to a pack member that they have a strong connection with, meaning a close social connection. Scientists tested these wolves’ saliva for cortisol, which is a stress hormone, and found that there were negligible results. It wasn’t anxiety causing these wolves to howl for each other. Rather, it may have been affection or another emotion not driven by anxiety.